Interlaminar shear test method for asphalt mixture composite board

Abstract

The invention discloses an interlaminar shear test method for an asphalt mixture composite board. The method comprises the following steps: preparing an asphalt mixture composite board test piece; putting the obtained asphalt mixture composite board test piece into an environmental box for heat preservation; the testing machine is adjusted to the testing temperature, and the asphalt mixture composite board test piece obtained after heat preservation is placed on a special clamp; vertically and downwards loading the asphalt mixture composite board test piece at a constant speed, and collecting pressure load and vertical displacement; and calculating the shear strength and the interlayer bonding coefficient. According to the interlayer shear test method for the asphalt mixture composite board, the problem that an interlayer shear test method special for the asphalt mixture does not exist in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of traffic materials, and particularly relates to a method for interlayer shearing test of asphalt mixture composite board. BACKGROUND

[0002] The asphalt surface layer is a layered composite system composed of different types of asphalt mixture. Obviously, the connection effect between different structural layers is closely related to the service performance of the asphalt pavement. If the interlayer connection is poor, the different structural layers are prone to push away due to insufficient shear resistance under the action of vehicle load and high temperature weather, causing the occurrence of pavement diseases. Therefore, improving the interlayer connection of the asphalt surface layer and enhancing the interlayer shear resistance between the structural layers are of great significance to ensure the durability of the asphalt pavement.

[0003] However, the existing specifications, standards and documents do not find a special interlayer shearing test method for asphalt mixture, which affects the effect of durability detection of the asphalt mixture. SUMMARY

[0004] The purpose of the present application is to provide a method for interlayer shearing test of asphalt mixture composite board, which solves the problem that there is no special interlayer shearing test method for asphalt mixture in the prior art.

[0005] In order to solve the above technical problems, the present application discloses a method for interlayer shearing test of asphalt mixture composite board, which is implemented according to the following steps:

[0006] Step 1, preparing an asphalt mixture composite board test piece;

[0007] Step 2, placing the asphalt mixture composite board test piece obtained in step 1 into an environmental box for heat preservation;

[0008] Step 3, adjusting the test machine to the test temperature, and placing the asphalt mixture composite board test piece after heat preservation in step 2 on a special fixture;

[0009] Step 4, vertically loading the asphalt mixture composite board test piece at a constant speed, and collecting the pressure load and vertical displacement;

[0010] Step 5, calculating the shear strength and interlayer bonding coefficient according to formula (1) and formula (2);

[0011]

[0012] In the formula, τ is the shear strength, the unit is MPa; P is the pressure load when the maximum shear occurs, the unit is KN; S is the interlayer shearing area, the unit is mm 2 ; K is the interlayer bonding coefficient, the unit is N / m 3 ; Δu is the relative vertical displacement between layers, the unit is m.

[0013] The technical scheme of the present application also has the following characteristics:

[0014] As a further improvement of the technical scheme of the present application, in the step 1, the preparation of the asphalt mixture composite board test piece is specifically implemented according to the following steps:

[0015] Step 1.1, fill the asphalt mixture into a single-layer rutting board test mold with a thickness of 80mm, and use a compaction hammer to compact it fully, and use a wheel roller to roll it back and forth until the thickness of the test piece reaches 80mm, and repeat the process to make the lower layer board test piece;

[0016] Step 1.2, after cooling for 24h, demold the lower layer board test piece, and place it into a double-layer rutting board test mold with a thickness of 140mm, and sprinkle 0.45kg / m 2 of tack coat oil on the surface;

[0017] Step 1.3, fill the asphalt mixture into a double-layer rutting board test mold with a thickness of 140mm, and use a compaction hammer to compact it fully; then, use a wheel roller to roll it back and forth until the total thickness of the test piece reaches 140mm, thereby completing the preparation of the middle and lower layer board test piece;

[0018] Step 1.4, after cooling for 24h, demold the middle and lower layer board test piece, and place it into a three-layer rutting board test mold with a thickness of 180mm, and sprinkle 0.45kg / m 2 of tack coat oil on the surface;

[0019] Step 1.5, fill the asphalt mixture into a three-layer rutting board test mold with a thickness of 180mm, and use a compaction hammer to compact it fully; then, use a wheel roller to roll it back and forth until the total thickness of the test piece reaches 180mm, thereby completing the preparation of the test piece.

[0020] As a further improvement of the technical scheme of the present application, in the step 2, the temperature of the environmental incubator is 60℃, with an error of ±0.5℃; and the incubation time is not less than 6h.

[0021] As a further improvement of the technical scheme of the present application, in the step 3, the test temperature is 60℃, and the constant temperature is maintained for not less than 30min; the clamp comprises a base and a pressure head, and the center of the base is protruded on both sides, and the center of the pressure head is protruded.

[0022] As a further improvement of the technical scheme of the present application, in the step 4, the press machine is loaded vertically downward at a constant speed of 10mm / min.

[0023] Compared with the prior art, the asphalt mixture composite board interlayer shear test method of the present application has the following advantages:

[0024] (1) The asphalt mixture composite board interlayer shear test method of the present application can accurately obtain interlayer shear performance data by preparing a test piece composed of three-layer rutting plates to simulate the interlayer of the asphalt mixture composite board, applying pressure to the test piece by a press, and completing the interlayer shear test.

[0025] (2) The asphalt mixture composite board interlayer shear test method of the present application has simple construction method, low cost, and can quickly and accurately complete the interlayer shear test, and has good market promotion and use prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural schematic diagram of a clamp in the asphalt mixture composite board interlayer shear test method of the present application.

[0027] Figure 2 is a construction process diagram of the asphalt mixture composite board interlayer shear test method of the present application. DETAILED DESCRIPTION

[0028] The technical solutions of the present application will be further described in detail below in combination with the description of the drawings and specific embodiments.

[0029] The asphalt mixture composite board interlayer shear test method of the present application is specifically implemented according to the following steps:

[0030] Step 1, preparing an asphalt mixture composite board test piece, specifically including:

[0031] Step 1.1, filling the asphalt mixture into a single-layer rutting plate test mold with a thickness of 80mm, tamping it with a tamping hammer, and using a wheel roller to roll it back and forth until the thickness of the test piece reaches 80mm, repeating the preparation process to prepare the lower layer test piece;

[0032] Step 1.2, after cooling for 24h, demolding, placing the lower layer test piece into a double-layer rutting plate test mold with a thickness of 140mm, and spraying 0.45kg / m 2 adhesive layer oil on the surface;

[0033] Step 1.3, filling the asphalt mixture into a double-layer rutting plate test mold with a thickness of 140mm, tamping it with a tamping hammer, and then using a wheel roller to roll it back and forth until the total thickness of the test piece reaches 140mm, thereby completing the preparation of the middle and lower layer test piece;

[0034] Step 1.4, after cooling for 24h, demolding, placing the middle and lower layer test piece into a three-layer rutting plate test mold with a thickness of 180mm, and spraying 0.45kg / m 2 adhesive layer oil on the surface;

[0035] Step 1.5, the asphalt mixture is filled into a three-layer rutting plate test mold with a thickness of 180mm, and is tamped with a compaction hammer; then, a wheel roller is used to roll back and forth until the total thickness of the test piece reaches 180mm, so as to complete the preparation of the test piece;

[0036] Step 2, the asphalt mixture composite board test piece obtained in step 1 is placed in an environmental oven; the temperature of the environmental oven is 60 DEG C, and the error is ± 0.5 DEG C; the temperature holding time is not less than 6h.

[0037] Step 3, the test machine is adjusted to the test temperature, and the asphalt mixture composite board test piece after temperature holding in step 2 is placed on the clamp; wherein: the test temperature is 60 DEG C and the constant temperature is not less than 30min;

[0038] As shown in Figure 1 The clamp comprises a base and a pressure head, the center of the base is protruded on both sides, the center of the pressure head is protruded, the test piece is placed between the two protrusions of the base, and the protrusion of the pressure head is pressed on the top of the test piece.

[0039] Step 4, the press machine vertically loads the asphalt mixture composite board test piece at a constant speed of 10mm / min, and collects the pressure load and vertical displacement;

[0040] Step 5, the shear strength and interlayer bonding coefficient are calculated according to formula (1) and formula (2);

[0041]

[0042] In the formula: τ is the shear strength, the unit is MPa; P is the pressure load when the maximum shear occurs, the unit is KN; S is the interlayer shear area, the unit is mm 2 ; K is the interlayer bonding coefficient, the unit is N / m 3 ; Δu is the relative vertical displacement between layers, the unit is m.

[0043] Application example

[0044] In combination Figure 2 , the application discloses a kind of asphalt mixture composite board interlayer shear test method, specifically according to steps implementation:

[0045] Step 1, prepare asphalt mixture composite board test piece, specifically including:

[0046] Step 1.1, the asphalt mixture is filled into a single-layer rutting plate test mold with a thickness of 80mm, and is tamped with a compaction hammer; a wheel roller is used to roll back and forth until the thickness of the test piece reaches 80mm, and the preparation process is repeated to make the lower plate test piece;

[0047] Step 1.2, after cooling for 24h, the lower plate specimen is placed into a double-layered rutting plate test mold with a thickness of 140mm, 0.45kg / m 2 Binder oil;

[0048] Step 1.3, the asphalt mixture is filled into the double-layered rutting plate test mold with a thickness of 140mm, and is tamped with a compaction hammer; then, a wheel roller is used to roll back and forth until the total thickness of the specimen reaches 140mm, thereby completing the preparation of the middle and lower plate specimen;

[0049] Step 1.4, after cooling for 24h, the middle and lower plate specimen is placed into a three-layered rutting plate test mold with a thickness of 180mm, 0.45kg / m 2 Binder oil;

[0050] Step 1.5, the asphalt mixture is filled into the three-layered rutting plate test mold with a thickness of 180mm, and is tamped with a compaction hammer; then, a wheel roller is used to roll back and forth until the total thickness of the specimen reaches 180mm, thereby completing the preparation of the specimen;

[0051] Step 2, the specimen is placed into an environmental box with a temperature of 60℃±0.5℃ for not less than 6h;

[0052] Step 3, the power is turned on to start the testing machine, the temperature controller is opened, and the testing temperature (60℃) is reached in the device and kept constant for not less than 30min;

[0053] Step 4, after the specimen and the testing machine are kept at temperature, the specimen is placed on the clamp;

[0054] Step 5, the testing machine is started, the press machine is loaded vertically downward at a constant speed of 10mm / min, and the pressure load change of the pressure sensor and the displacement change of the corresponding vertical displacement sensor are automatically collected by the data acquisition system until the interlayer shear failure of the specimen occurs, and the test is stopped.

[0055] After the test is completed, the maximum shear load P is recorded as 9.72KN, the interlayer shear area S is recorded as 90000mm 2 , the interlayer relative displacement Δu is recorded as 0.00835m, the shear strength τ is calculated as 0.108MPa, and the interlayer bonding coefficient K is calculated as 1.293×10 7 , and the calculation formula is as follows.

[0056]

[0057] In the formula, τ is the shear strength, MPa; P is the maximum shear load, KN; S is the interlayer shear area, mm 2 ; K is the interlayer bonding coefficient, N / m 3; Δu is the relative displacement between layers, m.

[0058] The parallel test number should be not less than 3 times, and the result is taken as average value;

[0059]

[0060] The average value is obtained as:

[0061]

[0062] The above description shows and describes several preferred embodiments of the invention, but as previously described, it should be understood that the invention is not limited to the forms disclosed herein, should not be considered as excluding other embodiments, and can be used in various other combinations, modifications and environments, and can be modified within the scope of the inventive concept described herein, by the above teaching or related technical or knowledge. The modifications and changes made by the person skilled in the art without departing from the spirit and scope of the invention shall be within the protection scope of the claims of the invention.

Claims

1. A method of interlaminar shear testing of an asphalt composite slab, characterized by, The steps are as follows: Step 1, preparing the asphalt mixture composite board test piece; Step 2, placing the asphalt mixture composite board test piece obtained in step 1 into an environmental box for heat preservation; Step 3, adjusting the testing machine to the testing temperature, and placing the asphalt mixture composite board test piece after heat preservation in step 2 on a special fixture; Step 4, vertically loading the asphalt mixture composite board test piece at a constant speed, and collecting the pressure load and vertical displacement; Step 5, calculating the shear strength and interlayer bonding coefficient according to formula (1) and formula (2); Where: τ is the shear strength, in MPa; P is the pressure load at which the maximum shear occurs, in KN; S is the interlayer shear area, in mm 2 ; K is the interlayer bond coefficient, in N / m 3 ; Δu is the relative vertical displacement between the layers, in m.

2. The method of claim 1, wherein, In the step 1, the preparation of the asphalt mixture composite board test piece is specifically implemented according to the following steps: Step 1.1, filling the asphalt mixture into a single-layer rutting plate test mold with a thickness of 80 mm, tamping it sufficiently with a tamping hammer, and using a wheel roller to roll it back and forth until the thickness of the test piece reaches 80 mm, repeating the process to prepare the lower layer test piece; Step 1.2, after cooling for 24 h, the lower plate specimen was placed in a double-layered rut plate test mold with a thickness of 140 mm, and 0.45 kg / m2of tack coat was sprinkled on the surface 2 tack coat oil; Step 1.3, filling the asphalt mixture into a double-layer rutting plate test mold with a thickness of 140 mm, tamping it sufficiently with a tamping hammer; then, using a wheel roller to roll it back and forth until the total thickness of the test piece reaches 140 mm, thereby completing the preparation of the middle and lower layer test piece; Step 1.

4. After 24 h of cooling, the middle and lower plate specimens were demolded and placed in a three-layer rut plate test mold with a thickness of 180 mm, and 0.45 kg / m2of tack coat was sprayed on the surface 2 tack coat oil; Step 1.5, filling the asphalt mixture into a three-layer rutting plate test mold with a thickness of 180 mm, tamping it sufficiently with a tamping hammer; then, using a wheel roller to roll it back and forth until the total thickness of the test piece reaches 180 mm, thereby completing the preparation of the test piece.

3. The method of claim 2, wherein, In the step 2, the temperature of the environmental heat preservation box is 60℃, with an error of ±0.5℃; the heat preservation time is not less than 6h.

4. The method of claim 3, wherein, In the step 3, the testing temperature is 60℃, and the constant temperature is not less than 30min; the fixture comprises a base and a pressure head, the center of the base is protruded on both sides, and the center of the pressure head is protruded.

5. The method of claim 4, wherein, In the step 4, the press machine vertically loads at a constant speed of 10mm / min.

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